Welding



Aug. 18, 1942. E. D. MORRIS WELDING Filed June 20, 1940 INVENTOR E DWARDD. M O

RRiS m ATTORNEY Patented Aug. 18, 1942 WELDING Edward D. Morris,

Chicago, 111., assignor to m kihnide Air Products Company, a corporationof Application June 20, 1940, Serial No. 341,426

8 Claims.

This invention relates to welding. and more particularly to-an improvedmethod of and apparatus for electric rivet or line welding in which thewelding operation is conducted beneath a blanket of granular fusiblemineral welding material.

In electric rivet or slot welding, the welding electrode is fed to alimited, substantially fixed area ofthe work salt is consumed and doesnot traverse the work to any substantialextent, remaining substantiallyin the same spot with respect to the work. When such electric rivet orslot welding is carried out beneath a blanket of granular weldingmaterial, the molten slag formed by fusion of the material during thewelding operation tends to build up above the welding puddle around thewelding electrode, causing the electrode to overheat above the actualwelding zone. This impairs the control of the welding action and oftenresults in poor fusion at the edges of the weld base. Such conditionsare not encountered when line welding with automatic welding machines asthe welding electrode is not only. fed toward the work but is alsotraversed along the work, encountering a fresh supply of the granularwelding material as it moves along the work, there not being asufficient time interval for the molten slag at any particular pointalong th line of welding to build up around the electrode. 7

It is therefore among the objects of this invention to provide a methodof electric rivet or line welding, in which a fusible electrode isadvanced to the work through a column of granular welding materialsupported above the weld-' Fig. 5 is a perspective view of a linealwelding device embodying the principles of the invention. Generallyspeaking, the objects of the invention are accomplished by advancing afusible electrode to the work through a horizontally stationary verticalcolumn of granular fusible min-- eral welding material supported abovethe welding puddle. The column of material is sufllciently high that thehydrostatic head created thereby will prevent the molten slag, formed byfusion of. the material due to the passage of an electric currentthrough the material from the electrode to the work, from building uparound the welding electrode, which, in rivet or slot welding does notmove horizontally relatively to the work to any substantial extent. Theweight of the column of material is suillcient to substantiallycounteract or neutralize the hydrostatic head created by the tendency ofthe molten slag to rise up along the electrode. Thus, by the presentinvention, this molten slag is forced to flow laterally or radially awayfrom the electrode. To maintain the column of material at the heightrequisite to create the necessary hydrostatic head, a continuous supplyof material is fed to the welding region.

- One form of apparatus for practicing the ing puddle; to provide such amethod in which molten slag, formed by fusion of the welding material,is forced to flow laterally or radially away from the electrode toprevent such slag from building up around the electrode and overheatingthe same above the welding puddle; and to provide a simple andeconomically constructed welding apparatus for practicing such method.Other objects will become apparent as the description proceeds.

The principles of the invention will be understood from the followingdescription and the accompanying drawing, in which:

Fig. l is a sectional view of a rivet welding device embodying theprinciples of the invention;

Fig. 2 is a perspective view of a portion of the device of Fig. 1;

Figs. 3 and 4 are perspective views of electrode guiding means which maybeused with the device of Fig. 1; and

method -of the invention desirably includes a welding materialchamberfor containing a sui'll-. cient amount of the welding material tofurnish a substantially continuous supply of material to the weldingregion and maintain a horizontally stationary column of the materialaround the welding electrode above the welding puddle during the entirewelding operation. Supporting means, preferably engaging the work, holdsthe welding material chamber in spaced relation to the work to providespace for the free flow of the molten slag-laterally or radially awayfrom the electrode. Guiding means for the electrode are desirablyprovided in the apparatus and may be formed to permit manipulation ofthe electrode laterally of the welding region.

Referring more particularly to the drawing, the

apparatus illustrated in Figs. 1 and 2 comprises a feeding device Dparticularly adapted to the formation of rivet welds between a pair ofmetal plates A and B. The plate B rests on the plate A and is formedwith an aperture C designed to receive molten weld metal deposited froma fusible metal electrode E arranged in operative relation to the work.In forming a rivet weld between plates A and B in the aperture 0, anelectric current is passed from the electrode to the work through agranular fusible mineral. welding material G, preferably. oi. the typedescribed and claimed in U. 8. Patent No. 2,048,960, issued in the namesof Jones, Kennedy. and Rotermund.

"'"'Fusion of this welding material forms a molten slag S which tends tobuild up around electrode E. causing overheating of the electrode abovethe weldingv puddle, impairing control of the welding operation andoften. resulting in poor fusion at the edges of the weld base. Thepresent invention, as will appear more iully hereinafter, is directed toa method of and apparatus for pre-" venting this undesirable condition.

The device D comprises an outer cylindrical member iii adapted to restupon the work an an inner cylindrical member H which acts as a supportfor a welding rod guiding ,means, -Means, such as an annular plate-l4is:secure'd to the outer member is at a point spaced above the innercylindrical member 52 may be secured; as by welding or otherwise.delivery means are provided, and as shown, this means comprises aninverted truncated conical j hopper 18 which extends between theaperture is and the upper end of member if The larger 5 or seam welds.

Welding material r o 7, a, 57 v '3, "0f the disc at isisatddnsnytdnssneiaien the rivet welds are of larger size,

Fig. 5 illustrates the application of the principles of the invention tothe formation of lineal Inv this embodiment oi the invention, plates P,P are arranged with their adiaoent bevelled edges 56 in abutment to forma welding groove or V. The welding apparatus in-thls instance comprisesa generally rectangudevice 1 D, inc-ludi ng-tg an'outerapair of hori-'onta'llyfi spaced aridiffpalrallel' .v'ertical members 52 correspondingto the member as of Fig. 1 and an inner pair of horizontally spaced andparallel vertical members 54 corresponding to 155 the member l2 ofFig. 1. An inwardly extendlate 58 is secured to each memtends tower thecenter of the device. The innor members ,j5s are each securedlongitudinally f' the'iriner'end of one of the horizontal plates 8; andare formed with cut-away portions 58 unil ar to th 3 out way portions ofend or the hopper i8 is attached to the upper g end of the member ID andits smaller endie secured to the plate it and the member, l2 adiacentthe aperture IS. The wall of the. inner;

member 12 has several cut-away portions 29;; h 1 a, which are preferablymade in such a mannenf if that some uncut metal remains at the top andbottom of the inner member i2, forming rings; 22 and 24 which act asstructural supports. The; 1

"85 I4 and in engagement with the work constitutes 1; means-supportingthe welding material deliv-f ery means in spaced relation tothe work to;provide for free flow of the. slag S laterally or? radially away fromthe electrode E. In rivet welding with the present invention? the deviceD is placed upon the work so that it. is substantially centered over theaperture C.

portion 26 of the wall of member l0 belowplate The welding rod orelectrode E, preferably of bare or uncoated metal, is advanced towardthe work along the center line of the feedingidevice D, and the granularmaterial G is fed into the;

hopper l8 and flows through the cut-away por-"g tions 20 of the innermember l2 to the welding region around. the electrode. As the welding"fio' w'eldifig mat'eflalfiigfl operation proceeds, the welding materialin the welding zone becomes molten due to the passage of a relativelyheavy electric current from theQ- fusing end of the electrode E throughthe material to the work. This molten slag is prevented from building uparound the electrode and is J welding V materiali'firo'm til i, L,region or thel'wield This "thereby prevents anaccu ulat ri thereoiaround the lower rend ot theelect The slagi's therev by prevented froerheatf n theelectrode.

While. fc'ertai mbocmients or theg iilvention a have been cheesesandfdescribed m sqme detailgit will beobvious to. those ,skilledin theart the decaused to flow laterally or radially away from} thatthe-inventiommay.befotherwiset embodied the electrode al ne the top ofthe work by e, i and that therraavgdimemong andlinterrelahQrizmtanystationary supported column 1' .tionof partsrnayl bechange thin thescope of new granular material continuously fedjto the th d g mg a Iwelding zone and supported on the w'eldin'gpud- ,iv w is aim d, l F

dle by the feedin device I 1 I A- method o electri ve, xweldlnguwhich Ifdesired, guiding means made of a suitable cqmptryiseshdpqsitmgafgmnulagg fuslblednmeml non-conductor of electricity, as shown in-Figs.welding: matgnia l upon mmhm t t n 3 and 4, maybe attached to the top ofthe inlit fl d gr r f thetworkj; insertings theggend of a ner member 52o ui the Welding B T d fusible welding electrodeintozsaid'materialrpassthe work. As shown in F this means .-;-1isingian'electricmurrentiiromatheaend'ofsaid eleccomprise a disc 3d formed with acircularhole 86 which acts as a centering guide for theiweldingelectrode E. If desired, the means shownw. in Fig. 4 may be used, whichmeans comprises a disc 38 formed with an elongated aperture Ml.v so thatthe electrodemay be manipulated latorally of the welding region orpuddle. The use- :trode athroughisaid materialitoe'such liniited;substantially fixed areafof the wor ing during ther'ent'ire' wl he'welding pud'dl electrode through said material to such limited,

substantially fined area of the work; and continuously feeding a newsupply of said material to 'such limited, substantially fixed area ofthey work as said material is fused by said electric current tomaintain, during the entire welding operation, a horizontally stationarycolumn of said welding material above such limited area and surroundingsaid electrode.

3. Welding apparatus comprising, in combination, a cylindrical memberadapted 'to be supported on the work; a centrally apertured annularplate secured to said member above its lower end; and a conical hopperextending between the aperture in said plate and the upper edge of saidmember.

4. In the combination claimed in claim 3, apertured welding electrodeguiding means supported on said plate in alignment with the aperturetherein.

5. Welding apparatus comprising, in combination, a cylindrical memberadapted to rest on the work to be welded; an inverted conical hopperhaving its larger end secured to the upper end of said member and itssmaller end disposed in spaced relation to the work; and means securingthe smaller end of said hopper to said member.

6. Welding apparatus comprising, in combination, an outer cylindricalmember adapted to rest upon the work;. an annular plate secured to saidouter cylindrical member at a point spaced above the work; an innercylindrical member secured to said annular plate; and welding rodguiding means attached to the top of said inner cylindrical member.

'7. Welding apparatus as claimed in claim 6, including an invertedconical hopper having its larger end attached to the upper end of saidouter cylindrical member and its smaller end attached to the lower endof said inner cylindrical member and to said annular plate.

8. Welding apparatus as claimed in claim 6, in which said innercylindrical member is formed with cutaway portions in such a manner thatuncut metal remains at the top and bottom of said inner cylindricalmember forming riims acting as structural supports.

EDWARD D. MORRIS.

